CMOS battery replacement

[Benjamin Deering]

On Fri, 11 Dec 2015 15:38:54 -0800
Andrew Schenck <andrew at springahead.com> wrote:

> That's a lot more work than I had hoped.  Thanks very much for the
> info though.  If I'm going to be soldering I might as well try to fix
> the USB port and GPS port at the same time.
> 
> -Andrew
> 
> On 12/11/2015 1:30 PM, Benjamin Deering wrote:
> > The backup battery (supercap?) is welded to its bracket and
> > won't push out.
> >
> > I replaced the backup batteries in my GTA02s with supercaps several
> > years ago.
> > http://www.jeepingben.net/zen/zenphoto/index.php?album=2010/freerunner_supercap_install
> >
> > The parts I used didn't match the original footprint so it was a
> > little work.  If you get the exact replacement part, it would be
> > easy if you have soldering experience.
> >
> > I vaguely remember a software problem causing the line that charges
> > the backup bat/cap not being set high.
> >
> > Good luck,
> >
> > Ben
> >
> > On Fri, 11 Dec 2015 12:26:54 -0800
> > Andrew Schenck <andrew at springahead.com> wrote:
> >  
> >> The secondhand GTA04 I have now is pretty beat up and can't charge
> >> because the USB port is disconnected.  I've been using a spare
> >> GTA02 as a charger, but every time I switch out batteries the
> >> clock resets to 12/12/1999 16:00 and it's a pain to re-set it
> >> since network time doesn't work.  I couldn't find any information
> >> on the wiki about replacing the CMOS battery to solve this
> >> problem; has anyone here dealt with this same problem before and
> >> have recommendations?
I was successful in fixing the USB port, but never tried the GPS port.
The GPS port is under a lot of stress when the board is installed.

I ended up giving up on the traces and soldering thin wires to the ESD
protection chip and to the leads on the jack.

After getting the USB port connected electrically, I used JB weld epoxy
to fix it mechanically.  The repair lasted years including some pretty
rough use and being reflow soldered.

Good luck,

Ben

> >>
> >> I disassembled a GTA02 enough to see the battery, but it didn't
> >> yield to gentle pressure trying to slide out of its bracket and I
> >> don't want to destroy things too badly in my attempt to fix them
> >> so I didn't push too hard.  Because of this, I don't even know the
> >> exact type of button cell to buy to replace it.  Any help would be
> >> appreciated.
> >>
> >> Thanks,
> >> -Andrew
> >>
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> >
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